Organic light emitting display device

ABSTRACT

An organic light emitting display (OLED) device is disclosed. The OLED device includes a substrate configured to include a sub-pixel defined into an emission region and a driving region. A first bank pattern configured to define the emission region of the sub-pixel is formed on the substrate. A second bank pattern configured to include an opening, which exposes the emission region and a part of the driving region, is formed on a part of an upper surface of the first bank pattern. An organic emission layer is formed in the opening. As such, the occupied area of the organic emission layer becomes wider. Therefore, the thickness deviation of the organic emission layer is prevented or minimized.

The present application is a continuation of U.S. patent applicationSer. No. 14/582,683 filed Dec. 24, 2014, now allowed, which claimspriority under 35 U.S.C. §119(a) of Korean Patent Application No.10-2014-0126207 filed on Sep. 22, 2014, both of which are herebyincorporated by reference in its entirety.

BACKGROUND

1. Field of the Disclosure

The present application relates to an organic light emitting display(OLED) device. More particularly, the present application relates to anOLED device adapted to prevent the generation of a thickness deviationand to a manufacturing method thereof.

2. Description of the Related Art

Nowadays, display devices have been rapidly developed with theadvancement of information communication. Among the display devices, anOLED device using a self-luminous element does not require a separatebacklight unit. In accordance therewith, the OLED device has features ofbeing thinner and lower power consumption compared to the other displaydevices.

In general, an organic light emitting element used in the OLED devicecan include an anode electrode, a cathode electrode and an organicemission layer interposed between the two electrodes. Such an organiclight emitting element enables generates excitons by recombining holesand electrons from the anode and cathode electrodes into the organicemission layer. Also, the organic light emitting element emits light bythe excitons transitioning from an excited state to a stable state.

The organic emission layer has been mainly formed using a vapordeposition method. Recently, an ink-jet printing process is being usedto form the organic emission layer on a large-sized substrate.

The ink-jet printing process feeds nozzles along a horizontal directionof sub-pixels and drops a liquefied organic emission material into eachof the sub-pixels through the nozzles. However, it is difficult tosecure enough nozzles opposite to a single sub-pixel due to thestructure of the OLED device. Due to this, if at least one of thenozzles shows an abnormity at the formation of the organic emissionlayer, thickness deviations of the organic emission layer must begenerated.

The thickness deviation of the organic emission layer can cause a stainwithin a sub-pixel. Moreover, if the organic emission layer is appliedto a high definition OLED device, the number of nozzles necessary toform the organic emission layer into each sub-pixel must be reducedmore. For this reason, the thickness deviation of the organic emissionlayer must be very sensitive to an abnormal nozzle.

BRIEF SUMMARY

Accordingly, embodiments of the present application are directed to anOLED device that substantially obviates one or more of problems due tothe limitations and disadvantages of the related art, as well to amethod of manufacturing the same.

The embodiments provide a display device and a manufacturing methodthereof which are adapted to prevent or minimize thickness deviation ofan organic emission layer by forming additional bank pattern with anopening which exposes a part of a driving domain within a sub-pixelregion.

Additional features and advantages of the embodiments will be set forthin the description which follows, and in part will be apparent from thedescription, or may be learned by practice of the embodiments. Theadvantages of the embodiments will be realized and attained by thestructure particularly pointed out in the written description and claimshereof as well as the appended drawings.

An OLED device according to a general aspect of the present embodimentincludes a substrate configured to include a sub-pixel defined into anemission region and a driving region. A first bank pattern configured todefine the emission region of the sub-pixel is formed on the substrate.A second bank pattern configured to include an opening, which exposesthe emission region and a part of the driving region, is formed on apart of an upper surface of the first bank pattern. An organic emissionlayer is formed in the opening. As such, the occupation area of theorganic emission layer becomes wider. Therefore, the thickness deviationof the organic emission layer is prevented or minimized.

Other systems, methods, features and advantages will be, or will become,apparent to one with skill in the art upon examination of the followingfigures and detailed description. It is intended that all suchadditional systems, methods, features and advantages be included withinthis description, be within the scope of the present disclosure, and beprotected by the following claims. Nothing in this section should betaken as a limitation on those claims. Further aspects and advantagesare discussed below in conjunction with the embodiments. It is to beunderstood that both the foregoing general description and the followingdetailed description of the present disclosure are exemplary andexplanatory and are intended to provide further explanation of thedisclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the embodiments and are incorporated herein andconstitute a part of this application, illustrate embodiment(s) of thepresent disclosure and together with the description serve to explainthe disclosure. In the drawings:

FIG. 1 is a cross-sectional view showing an OLED device according to afirst embodiment of the present disclosure;

FIG. 2 is a planar view illustrating formation procedures of an organicemission layer according to a first embodiment of the present disclosureand a comparable embodiment;

FIG. 3 is a cross-sectional view showing an OLED device according to asecond embodiment of the present disclosure;

FIG. 4 is a planar view illustrating formation procedures of an organicemission layer according to a second embodiment of the presentdisclosure and a comparable embodiment;

FIG. 5 is a cross-sectional view showing an OLED device according to athird embodiment of the present disclosure; and

FIG. 6 is a planar view illustrating formation procedures of an organicemission layer according to a third embodiment of the present disclosureand a comparable embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings. These embodiments introduced hereinafter are provided asexamples in order to convey the spirit of the invention to the ordinaryskilled person in the art. Therefore, the embodiments may be embodied ina different shape, so are not limited to these embodiments describedhere. In the drawings, the size, thickness and so on of a device can beexaggerated for convenience of explanation. Wherever possible, the samereference numbers will be used throughout this disclosure including thedrawings to refer to the same or like parts.

FIG. 1 is a cross-sectional view showing an OLED device according to afirst embodiment of the present disclosure. Referring to FIG. 1, theOLED device according to a first embodiment of the present disclosureincludes a substrate 100 provided with a plurality of sub-pixels whichis used to display an image. The sub-pixel can be defined into anemission region and a driving region prepared to drive the emissionregion. The OLED device includes an organic light emitting elementformed in the emission region of the sub-pixel region. Also, the OLEDdevice includes a thin film transistor Tr and a capacitor Cst which areformed in the driving region of the sub-pixel region.

The organic light emitting element includes first electrode 114. Also,the organic light emitting element includes a second electrode and anorganic emission layer which are not shown in the drawing. The secondelectrode is disposed opposite to the first electrode 114. The organicemission layer is formed between the first electrode 114 and the secondelectrode.

The thin film transistor Tr includes a semiconductor layer 104, a gateinsulation film 106, a gate electrode 107, a source electrode 110 and adrain electrode 111 which are sequentially formed on the substrate 100.The capacitor Cst includes a capacitor electrode 112 and anothersemiconductor layer 105 disposed thereunder.

In detail, the semiconductor layer 104 of the thin film transistor Trand the semiconductor layer 105 of the capacitor Cst are formed on thesubstrate 100. The semiconductor layer 104 of the thin film transistorTr includes a drain region 101, a channel region 102 and a source region103.

The gate insulation film 106 is formed on the substrate 100 in such amanner as to cover the semiconductor layers 104 and 105. The gateelectrode 107 is formed on the gate insulation film 106 opposite to thechannel region 102 of the semiconductor layer 104 of the thin filmtransistor Tr. Such a gate electrode 107 can be formed from one ofcopper Cu, silver Ag, aluminum Al, chromium Cr, titanium Ti, tantalumTa, molybdenum Mo and alloys thereof. Although the gate electrode 107 isformed to have a single metal layer as shown in the drawing, the gateelectrode 107 can be formed by stacking at least two metal layers asneeded.

An interlayer insulation film 109 is formed on the entire surface of thesubstrate 100 provided with the gate electrode 107. Primary contactholes are formed in the interlayer insulation film 109 and the gateinsulation film 106. The primary contact holes expose the drain region101 and the source region 103.

Thereafter, the source electrode 110 and drain electrode 111 beingseparated from each other are formed on a part of the interlayerinsulation film 109 provided with the primary contact holes. The sourceelectrode 110 and the drain electrode 111 are connected to the sourceregion 103 and the drain region 101 of the thin film transistor Trthrough the primary contact holes. At the same time, the capacitorelectrode 112 is also formed on the interlayer insulation film 109opposite to the semiconductor layer 105 of the capacitor Cst. Thecapacitor electrode 112 can be formed from the same material as thesource and drain electrodes 110 and 111.

The source electrode 110, the drain electrode 111 and the capacitorelectrode 112 can be formed from one of copper Cu, silver Ag, aluminumAl, chromium Cr, titanium Ti, tantalum Ta, molybdenum Mo and alloysthereof. Although the source electrode 110, the drain electrode 111 andthe capacitor electrode 112 are formed to have a single metal layer asshown in the drawing, they can be formed by stacking at least two metallayers as needed.

In this manner, the thin film transistor Tr and the capacitor Cst areformed on the substrate 100. A region being occupied by the thin filmtransistor Tr and the capacitor Cst can be defined as the drivingregion.

A planarization film 113 is formed on the entire surface of thesubstrate 100 provided with the thin film transistor Tr and thecapacitor Cst. The planarization film 113 is used to planarize an unevensurface of the substrate 100 caused by the thin film transistor Tr.

Although not shown in the drawing, a passivation film can further beformed on the entire surface of the substrate 100 provided with the thinfilm transistor Tr and the capacitor Cst before the formation of theplanarization film 113. The passivation film can be used to protect thesource electrode 110, the drain electrode 111 and the capacitorelectrode 112.

A secondary contact hole exposing the drain electrode 111 of the thinfilm transistor Tr is formed in the planarization film 113. The firstelectrode 114 of the organic light emitting element is formed on a partof an upper surface of the planarization film 113. The first electrode114 is connected to the drain electrode 111 through the secondarycontact hole.

The first electrode 114 can be used as an anode electrode, but it is notlimited to this. In other words, the first electrode 114 can be used asa cathode electrode. As an example, the first electrode 114 used as theanode electrode will now be described.

Such a first electrode 114 can be formed in a single layer and from atransparent conductive material with a relatively high work function. Assuch, a bottom emission mode OLED device emitting light in a downwarddirection of the first electrode 114 can be implemented.

Alternatively, the OLED device can further include a reflective layerdisposed under the first electrode 114. In this case, a top emissionmode OLED device emitting light in an upward direction of the firstelectrode 114 can be implemented. The reflective layer reflects lightreceived through the first electrode 114 toward an upward direction ofthe first electrode 114.

However, the first electrode 114 is not limited to the structure shownin the drawing. Alternatively, the first electrode 114 can be formed ina multi-layered structure. For example, the first electrode 114 can beformed in a triple layered structure including sequentially stackedfirst through third layers.

The first layer and the third layer can be formed from a transparentconductive material. The transparent conductive material can be one ofindium-tin-oxide ITO and indium-zinc-oxide IZO. The second layer can bea reflective layer. In this case, the second layer can be formed fromone of a metal and a metal alloy. For example, the second electrode canbe formed from one of silver Ag and an alloy containing silver Ag. Sucha first electrode 114 reflects light progressing in the downwarddirection of the second electrode toward the upward direction of thesecond electrode. In accordance therewith, the top emission mode OLEDdevice can be implemented.

A first bank pattern 115 can be formed on the planarization film 113provided with the first electrode 114. The first bank pattern 115 candefine the emission region of the sub-pixel. Also, the first bankpattern 115 can be formed in such a manner as to expose a part of theupper surface of the first electrode 114 corresponding to the emissionregion.

A second bank pattern 116 can be formed on a part of an upper surface ofthe first bank pattern 115. In detail, the second bank pattern 116 canbe disposed in the driving region opposite to the capacitor Cst. Thesecond bank pattern 116 can be formed to have a higher height (or alarger thickness) than that of the first bank layer 115. As such, aconcentrated phenomenon of the organic emission layer toward anon-emission region can be prevented.

In accordance therewith, an opening exposing the emission region and apart of the driving region opposite to the thin film transistor Tr canbe formed by means of the second bank pattern 116. For the convenienceof explanation, the opening defined by the second bank pattern 116 willbe referred to as a first opening A. In other words, the first opening Acan expose the emission region and a part of the driving region which isprepared to drive the organic light emitting element disposed in theemission region.

An organic emission layer is disposed in the first opening A. In otherwords, the organic emission layer can be formed in such a manner as tocover the upper surface of the first bank pattern 115 and be surroundedby the second bank pattern 116.

The organic emission layer can be a single layer formed from an emissionmaterial. In order to enhance the luminous efficiency, the organicemission layer can be formed in a multi-layered structure. For example,the organic emission layer can include a hole injection layer, a holetransport layer, an emission material layer, an electron transport layerand an electron injection layer.

The organic emission layer can be formed using an ink-jet method whichjets or drops a liquefied organic emission material on the firstelectrode 114 and hardens the jetted or dropped emission material. Morespecifically, the organic emission layer can be prepared by supplyingthe first opening A with a pixel pigment through nozzles of an ink headopposite to the sub-pixel. If the organic emission layer is formed usingthe liquefied organic emission material, a large-sized display devicecan be efficiently manufactured and the manufacture procedure of thelarge-sized display device can be simplified.

In this way, the nozzles of the ink head for supplying the liquefiedorganic emission material can be opposite to not only the emissionregion but also a part of the driving region which is prepared to drivethe emission region. As such, a large quantity of organic emissionmaterial can be supplied to the sub-pixel. This results from the factthat the number of nozzles of the ink head opposite to the sub-pixel(i.e., the first opening A) increases. As such, the organic emissionlayer can be uniformly formed even though one of the nozzles of the inkhead shows an abnormality.

The OLED device according to the present disclosure can increase thenumber of nozzles of the ink head opposite to each sub-pixel by formingan additional bank pattern (i.e., the second bank pattern) with thefirst opening A which exposes the emission region and a part of thedriving region prepared with drive the emission region. The thicknessdeviation of the organic emission layer within the sub-pixel can beminimized even though one of the nozzles shows an abnormality in the jetof the liquefied organic emission material.

FIG. 2 is a planar view illustrating formation procedures of an organicemission layer according to a first embodiment of the present disclosureand a comparable embodiment. As shown in FIG. 2, a nozzle portion 200 isdisposed in the central region, sub-pixels of a comparative embodimentare arranged in the left side of the nozzle portion 200, and sub-pixelsof the first embodiment are arranged in the right side of the nozzleportion.

Referring to FIG. 2, the sub-pixels of the OLED devices according to thecomparative embodiment and the first embodiment can be defined into anemission region 10 prepared for the formation of an organic lightemitting element, and a driving region 20 prepared for the formation ofan thin film transistor and a capacitor.

Both of the first embodiment and the comparative embodiment allow afirst bank pattern 115 surrounding the emission region 10 and coveringthe driving region 20. As such, the emission region 10 can be exposed inan elliptical shape by the first bank pattern 115. In other words, thefirst bank pattern 115 can be used to define the sub-pixel region intothe emission region 10 and a non-emission region.

Unlike the comparative embodiment, the first embodiment further forms asecond bank pattern 116 exposing a part of the first bank pattern 115 inan elliptical shape. The exposed first bank pattern 115 can occupy anadjacent region to the emission region 10 and a part of the drivingregion 20 which is prepared to drive an organic light emitting elementon the emission region 10.

A pixel pigment for forming the organic emission layer can be suppliedto a substrate with the bank pattern through the nozzle portion. In thistime, the nozzle portion 200 used in the comparative embodiment must beopposite to only the emission region 10. On the other hand, the nozzleportion 200 used in the first embodiment can be opposite to not only theemission region 10 but also the driving region 20.

As such, the number of nozzles opposite to the sub-pixel of the firstembodiment can become larger than the number of nozzles opposite to thesub-pixel of the comparative embodiment. In accordance therewith, theorganic emission layer of the first embodiment can be more uniformlyformed compared to that of the comparative embodiment when the nozzleportion 200 shows an abnormality.

Also, the OLED device of the present disclosure allows the sub-pixels tobe arranged in a zigzag shape not a single line based on a horizontalaxis. In this case, the pixel pigment can be supplied to the emissionregion 10 and the driving region 20 through different nozzles from eachother. In accordance therewith, the quantity deviation of the pixelpigment within the emission region 10 and the driving region 20 can beminimized.

In this way, the OLED device according to a first embodiment of thepresent disclosure can form an additional bank pattern (i.e., the secondbank pattern 116) exposing the emission region 10 and a part of thedriving region 20 prepared for the emission region 10. As such, thenumber of nozzles of the ink head opposite to each sub-pixel canincrease at the formation of the organic emission layer. In accordancetherewith, a large quantity of organic emission material can be suppliedto each of the sub-pixels through a single scan.

Subsequently, an OLED device according to a second embodiment of thepresent disclosure will be described with reference to FIG. 3. FIG. 3 isa cross-sectional view showing an OLED device according to a secondembodiment of the present disclosure. The OLED display device of thesecond embodiment can include the same components as that of theprevious embodiment. As such, components of the second embodiment havingthe same function and shape as those of the previous embodiment will bereferred to by the same reference numbers and names. Also, thedescription of the second embodiment overlapping with the previousembodiment will be omitted.

Referring to FIG. 3, the OLED device according to a second embodiment ofthe present disclosure includes a substrate 100 provided with aplurality of sub-pixels regions which are used to display an image. Thesub-pixel can be defined into an emission region and a driving regionprepared to drive the emission region. The OLED device includes anorganic light emitting element formed in the emission region of thesub-pixel. Also, the OLED device includes a thin film transistor Tr anda capacitor Cst which are formed in the driving region of the sub-pixel.

The thin film transistor Tr includes a semiconductor layer 104, a gateinsulation film 106, a gate electrode 107, a source electrode 110 and adrain electrode 111 which are sequentially formed on the substrate 100.The capacitor Cst includes a capacitor electrode 112 and anothersemiconductor layer 105 disposed thereunder. The organic light emittingelement includes first electrode 114. Also, the organic light emittingelement includes a second electrode and an organic emission layer whichare not shown in the drawing. The second electrode is disposed oppositeto the first electrode 114. The organic emission layer is formed betweenthe first electrode 114 and the second electrode.

More specifically, the semiconductor layer 104 of the thin filmtransistor Tr and the semiconductor layer 105 of the capacitor Cst areformed on the substrate 100. The semiconductor layer 104 of the thinfilm transistor Tr includes a drain region 101, a channel region 102 anda source region 103.

The gate insulation film 106 is formed on the substrate 100 in such amanner as to cover the semiconductor layers 104 and 105. The gateelectrode 107 is formed on the gate insulation film 106 opposite to thechannel region 102 of the semiconductor layer 104 of the thin filmtransistor Tr. Such a gate electrode 107 can be formed from one ofcopper Cu, silver Ag, aluminum Al, chromium Cr, titanium Ti, tantalumTa, molybdenum Mo and alloys thereof. Although the gate electrode 107 isformed to have a single metal layer as shown in the drawing, the gateelectrode 107 can be formed by stacking at least two metal layers asneeded.

An interlayer insulation film 109 is formed on the entire surface of thesubstrate 100 provided with the gate electrode 107. Primary contactholes are formed in the interlayer insulation film 109 and the gateinsulation film 106. The primary contact holes expose the drain region101 and the source region 103.

Afterward, the source electrode 110 and drain electrode 111 beingseparated from each other are formed on a part of the interlayerinsulation film 109 provided with the primary contact holes. The sourceelectrode 110 and the drain electrode 111 are connected to the sourceregion 103 and the drain region 101 of the thin film transistor Trthrough the primary contact holes. At the same time, the capacitorelectrode 112 is also formed on the interlayer insulation film 109opposite to the semiconductor layer 105 of the capacitor Cst. Thecapacitor electrode 112 can be formed from the same material as thesource and drain electrodes 110 and 111.

The source electrode 110, the drain electrode 111 and the capacitorelectrode 112 can be formed from one of copper Cu, silver Ag, aluminumAl, chromium Cr, titanium Ti, tantalum Ta, molybdenum Mo and alloysthereof. Although the source electrode 110, the drain electrode 111 andthe capacitor electrode 112 are formed to have a single metal layer asshown in the drawing, they can be formed by stacking at least two metallayers as needed. In this manner, the thin film transistor Tr and thecapacitor Cst are formed on the substrate 100.

A planarization film 113 is formed on the entire surface of thesubstrate 100 provided with the thin film transistor Tr and thecapacitor Cst. A secondary contact hole exposing the drain electrode 111of the thin film transistor Tr is formed in the planarization film 113.The first electrode 114 of the organic light emitting element is formedon a part of an upper surface of the planarization film 113. The firstelectrode 114 is connected to the drain electrode 111 through thesecondary contact hole.

The first electrode 114 can be used as an anode electrode. Such a firstelectrode 114 can be formed in a single layer and from a transparentconductive material with a relatively high work function. As such, abottom emission mode OLED device emitting light in a downward directionof the first electrode 114 can be implemented.

Alternatively, the OLED device can further include a reflective layerdisposed under the first electrode 114. In this case, a top emissionmode OLED device emitting light in an upward direction of the firstelectrode 114 can be implemented. The reflective layer reflects lightreceived through the first electrode 114 toward an upward direction ofthe first electrode 114.

However, the first electrode 114 is not limited to the structure shownin the drawing. Alternatively, the first electrode 114 can be formed ina multi-layered structure. For example, the first electrode 114 can beformed in a triple layered structure including sequentially stackedfirst through third layers.

The first layer and the third layer can be formed from a transparentconductive material. The transparent conductive material can be one ofindium-tin-oxide ITO and indium-zinc-oxide IZO. The second layer can bea reflective layer. As such, the first electrode 114 reflects lightprogressing in the downward direction of the second electrode toward theupward direction of the second electrode. In accordance therewith, thetop emission mode OLED device can be implemented.

A first bank pattern 115 can be formed on the planarization film 113provided with the first electrode 114. The first bank pattern 115 candefine the emission region and a non-emission region of the sub-pixel.Also, the first bank pattern 115 can is formed in such a manner as toexpose a part of the upper surface of the first electrode 114corresponding to the emission region 10.

A second bank pattern 216 can be formed on a part of an upper surface ofthe first bank pattern 115. In detail, the second bank pattern 216 canbe disposed in the driving region opposite to the thin film transistorTr. The second bank pattern 216 can be formed to have a higher height(or a larger thickness) than that of the first bank layer 115.

In accordance therewith, an opening exposing the upper surface of thefirst electrode 114 within the emission region and a part of the drivingregion opposite to the thin film transistor Tr can be formed by means ofthe second bank pattern 216. For the convenience of explanation, theopening defined by the second bank pattern 216 will be referred to as asecond opening B.

In detail, the second opening B can expose the emission region and apart of the driving region opposite to the capacitor Cst. In otherwords, the second opening B can expose a single emission region and apart of an adjacent driving region thereto which is prepared to drive adifferent emission region.

An organic emission layer is disposed into the second opening B. Inother words, the organic emission layer can be formed in such a manneras to cover the upper surface of the first bank pattern 115 and besurrounded by the second bank pattern 216.

The organic emission layer can be a single layer formed from an emissionmaterial. In order to enhance the luminous efficiency, the organicemission layer can be formed in a multi-layered structure. For example,the organic emission layer can include a hole injection layer, a holetransport layer, an emission material layer, an electron transport layerand an electron injection layer.

The organic emission layer can be formed using an ink-jet method whichjets or drops a liquefied organic emission material on the firstelectrode 114 and then hardens the jetted or dropped emission material.More specifically, the organic emission layer can be formed by supplyingthe second opening B with a pixel pigment through nozzles of an ink headopposite to the sub-pixel.

In this way, the nozzles of the ink head for supplying the liquefiedorganic emission material can be opposite to not only the emissionregion of the respective sub-pixel but also a part of the driving regionof a different sub-pixel adjacent thereto. As such, a large quantity oforganic emission material can be supplied to each of the sub-pixelsthrough a single scan when the liquefied organic emission material isdropped on the pixel region.

The OLED device according to the present disclosure can increase thenumber of nozzles of the ink head opposite to each sub-pixel by formingan additional bank pattern (i.e., the second bank pattern) with thesecond opening B which exposes the emission region and a part of thedriving region prepared with drive the emission region. In accordancetherewith, the thickness deviation of the organic emission layer withinthe sub-pixel can be minimized even though one of the nozzles shows anabnormality in the jet of the liquefied organic emission material.

Also, a procedure of forming an organic emission layer according to asecond embodiment of the present disclosure will be described withreference to FIG. 4. FIG. 4 is a planar view illustrating formationprocedures of an organic emission layer according to a second embodimentof the present disclosure and a comparable embodiment. As shown in FIG.4, a nozzle portion 200 is disposed in the central region, sub-pixels ofa comparative embodiment are arranged in the left side of the nozzleportion 200, and sub-pixels of the second embodiment are arranged in theright side of the nozzle portion.

Referring to FIG. 4, the sub-pixels of the OLED devices according to thecomparative embodiment and the second embodiment can be defined into anemission region 10 prepared for the formation of an organic lightemitting element, and a driving region 20 prepared for the formation ofan thin film transistor and a capacitor.

Both of the second embodiment and the comparative embodiment allow afirst bank pattern surrounding the emission region 10 and covering thedriving region 20 to be formed on each of the sub-pixels. As such, theemission region 10 can be exposed in an elliptical shape by the firstbank pattern 115. In other words, the first bank pattern 115 can be usedto define the sub-pixel region into the emission region 10 and anon-emission region.

Unlike the comparative embodiment, the second embodiment further forms asecond bank pattern 216 exposing a part of the first bank pattern 115 inan elliptical shape. The exposed first bank pattern 115 can occupy anadjacent region to the emission region 10 of the respective sub-pixel.Also, the exposed first bank pattern 115 can occupy a part of thedriving region 20 which is formed adjacently to the emission region 10of the respective sub-pixel and prepared to drive the emission region 10of a different sub-pixel.

A pixel pigment for forming the organic emission layer can be suppliedto a substrate with the bank pattern through the nozzle portion. In thiscase, the nozzle portion 200 used in the comparative embodiment must beopposite to only the emission region 10. On the other hand, the nozzleportion 200 used in the second embodiment can be opposite to not onlythe emission region 10 of the respective sub-pixel but also an adjacentdriving region 20 thereto which is prepared to drive the emission region10 of another sub-pixel.

As such, the number of nozzles opposite to the sub-pixel of the secondembodiment can become larger than the number of nozzles opposite to thesub-pixel of the comparative embodiment. In accordance therewith, theorganic emission layer of the second embodiment can be more uniformlyformed compared to that of the comparative embodiment when the nozzleportion 200 shows an abnormality.

In this way, the OLED device according to a second embodiment of thepresent disclosure can form an additional bank pattern (i.e., the secondbank pattern 216) exposing the emission region 10 of the respectivesub-pixel and a part of an adjacent driving region 20 thereto which isprepared for the emission region 10 of another sub-pixel. As such, thenumber of nozzles of the ink head opposite to each sub-pixel canincrease at the formation of the organic emission layer. In accordancetherewith, a large quantity of organic emission material can be suppliedto each of the sub-pixels through a single scan.

Next, an OLED device according to a third embodiment of the presentdisclosure will be described with reference to FIG. 5. FIG. 5 is across-sectional view showing an OLED device according to a thirdembodiment of the present disclosure. The OLED display device of thethird embodiment can include the same components as that of the previousembodiment. As such, components of the third embodiment having the samefunction and shape as those of the previous embodiment will be referredto by the same reference numbers and names. Also, the description of thethird embodiment overlapping with the previous embodiment will beomitted.

Referring to FIG. 5, the OLED device according to a third embodiment ofthe present disclosure includes a substrate 100 provided with aplurality of sub-pixels which is used to display an image. The sub-pixelcan be defined into an emission region and a driving region prepared todrive the emission region. The OLED device includes an organic lightemitting element formed in the emission region of the sub-pixel region.Also, the OLED device includes a thin film transistor Tr and a capacitorCst which are formed in the driving region of the sub-pixel region.

The thin film transistor Tr includes a semiconductor layer 104, a gateinsulation film 106, a gate electrode 107, a source electrode 110 and adrain electrode 111 which are sequentially formed on the substrate 100.The capacitor Cst includes a capacitor electrode 112 and anothersemiconductor layer 105 disposed thereunder. The organic light emittingelement includes first electrode 114. Also, the organic light emittingelement includes a second electrode and an organic emission layer whichare not shown in the drawing. The second electrode is disposed oppositeto the first electrode 114. The organic emission layer is formed betweenthe first electrode 114 and the second electrode. The detaileddescription for the structures of the thin film transistor Tr and thecapacitor Cst will be omitted.

A planarization film 113 is formed on the entire surface of thesubstrate 100 provided with the thin film transistor Tr and thecapacitor Cst. A secondary contact hole exposing the drain electrode 111of the thin film transistor Tr is formed in the planarization film 113.The first electrode 114 of the organic light emitting element is formedon a part of an upper surface of the planarization film 113. The firstelectrode 114 is connected to the drain electrode 111 through thesecondary contact hole.

The first electrode 114 can be used as an anode electrode. Such a firstelectrode 114 can be formed in a single layer and from a transparentconductive material with a relatively high work function. As such, abottom emission mode OLED device emitting light in a downward directionof the first electrode 114 can be implemented.

Alternatively, the OLED device can further include a reflective layerdisposed under the first electrode 114. In this case, a top emissionmode OLED device emitting light in an upward direction of the firstelectrode 114 can be implemented. The reflective layer reflects lightreceived through the first electrode 114 toward an upward direction ofthe first electrode 114. However, the first electrode 114 is not limitedto the structure shown in the drawing. Alternatively, the firstelectrode 114 can be formed in a multi-layered structure.

A first bank pattern 115 can be formed on the planarization film 113provided with the first electrode 114. The first bank pattern 115 candefine the emission region and a non-emission region of the sub-pixel.Also, the first bank pattern 115 can be formed in such a manner as toexpose a part of the upper surface of the first electrode 114corresponding to the emission region 10.

A second bank pattern 316 can be formed on a part of an upper surface ofthe first bank pattern 115. In detail, the second bank pattern 316 canbe formed to have a higher height (or a larger thickness) than that ofthe first bank layer 115. The second bank pattern 116 can be disposed inthe driving region opposite to an intermediate region between the thinfilm transistor Tr and the capacitor Cst.

In accordance therewith, an opening exposing the emission region 10 anda part of the driving region 20 opposite to the thin film transistor Trand the capacitor Cst, by means of the second bank pattern 316. For theconvenience of explanation, the opening defined by the second bankpattern 316 will be referred to as a third opening C.

In detail, the third opening C can expose a single emission region. Thethird opening C can also expose a part of a driving region prepared todrive the emission region and a part of another driving region adjacentto the emission region.

An organic emission layer is disposed into the third opening C. In otherwords, the organic emission layer can be formed in such a manner as tocover the upper surface of the first bank pattern 115 and be surroundedby the second bank pattern 316.

The organic emission layer can be a single layer formed from an emissionmaterial. In order to enhance the luminous efficiency, the organicemission layer can be formed in a multi-layered structure. For example,the organic emission layer can include a hole injection layer, a holetransport layer, an emission material layer, an electron transport layerand an electron injection layer.

The organic emission layer can be formed using an ink-jet method whichjets or drops a liquefied organic emission material on the firstelectrode 114 and then hardens the jetted or dropped emission material.More specifically, the organic emission layer can be formed by supplyingthe second opening B with a pixel pigment through nozzles of an ink headopposite to the sub-pixel.

In this way, the nozzles of the ink head for supplying the liquefiedorganic emission material can be opposite to not only the emissionregion of the respective sub-pixel but also a part of a driving regionprepared to drive the emission region of the respective sub-pixel and apart of another driving region which is formed adjacently to theemission region of the respective sub-pixel and prepared to drive thedriving region of a different sub-pixel. As such, a large quantity oforganic emission material can be supplied to each of the sub-pixelsthrough a single scan when the liquefied organic emission material isdropped on the pixel region. Also, the number of nozzles of the ink headopposite to each sub-pixel can increase. In accordance therewith, thethickness deviation of the organic emission layer within the sub-pixelcan be minimized even though one of the nozzles shows an abnormality inthe jet of the liquefied organic emission material.

Continuously, a procedure of manufacturing an organic emission layeraccording to a third embodiment of the present disclosure will bedescribed with reference to FIG. 6. FIG. 6 is a planar view illustratingformation procedures of an organic emission layer according to a thirdembodiment of the present disclosure and a comparable embodiment. Asshown in FIG. 6, a nozzle portion 200 is disposed in the central region,sub-pixels of a comparative embodiment are arranged in the left side ofthe nozzle portion 200, and sub-pixels of the third embodiment arearranged in the right side of the nozzle portion.

Referring to FIG. 6, the sub-pixels of the OLED devices according to thecomparative embodiment and the third embodiment can be defined into anemission region 10 prepared for the formation of an organic lightemitting element, and a driving region 20 prepared for the formation ofan thin film transistor and a capacitor.

Both of the third embodiment and the comparative embodiment allow afirst bank pattern 115 surrounding the emission region 10 and coveringthe driving region 20 to be formed on each of the sub-pixels. As such,the emission region 10 can be exposed in an elliptical shape by thefirst bank pattern 115. In other words, the first bank pattern 115 canbe used to define the sub-pixel region into the emission region 10 and anon-emission region.

Unlike the comparative embodiment, the third embodiment further forms asecond bank pattern 316 exposing a part of the first bank pattern 115 inan elliptical shape. The exposed first bank pattern 115 can occupy anadjacent region to the emission region 10 of the respective sub-pixel.Also, the exposed first bank pattern 115 can occupy a part of a drivingregion 20, which is prepared to drive the emission region 10 of therespective sub-pixel, and an adjacent region thereto. Moreover, theexposed first bank pattern 115 can occupy a part of another drivingregion 20, which is prepared to drive the emission region 10 of adifferent sub-pixel, and an adjacent region thereto.

A pixel pigment for forming the organic emission layer can be suppliedto a substrate with the bank pattern through the nozzle portion. In thiscase, the nozzle portion 200 used in the comparative embodiment must beopposite to only the emission region 10. On the other hand, the nozzleportion 200 used in the third embodiment can be opposite to not only theemission region 10 of the respective sub-pixel but also a driving region20 prepared to drive the emission region of the respective sub-pixel andanother driving region prepared to drive the emission region 10 of adifferent sub-pixel.

As such, the number of nozzles opposite to the sub-pixel of the thirdembodiment can become larger than the number of nozzles opposite to thesub-pixel of the comparative embodiment. In accordance therewith, theorganic emission layer of the second embodiment can be more uniformlyformed compared to that of the comparative embodiment when the nozzleportion 200 shows an abnormality.

Although the present disclosure has been limitedly explained regardingonly the embodiments described above, it should be understood by theordinary skilled person in the art that the present disclosure is notlimited to these embodiments, but rather that various changes ormodifications thereof are possible without departing from the spirit ofthe present disclosure. Accordingly, the scope of the present disclosureshall be determined only by the appended claims and their equivalentswithout being limited to the detailed description.

1-17. (canceled)
 18. An organic light emitting display devicecomprising: a substrate configured to include a sub-pixel defined intoan emission region and a driving region; a first bank pattern disposedon the substrate and configured to define the emission region of thesub-pixel; a second bank pattern disposed on a part of an upper surfaceof the first bank pattern and configured to include an opening whichexposes the emission region and a part of the driving region; and anorganic emission layer disposed in the opening, wherein the opening iswider than the emission region.
 19. The organic light emitting displaydevice of claim 18, wherein the second bank pattern has a larger heightthan that of the first bank pattern.
 20. The organic light emittingdisplay device of claim 18, wherein the second bank pattern is disposedin the driving region opposite to a capacitor.
 21. The organic lightemitting display device of claim 18, wherein the opening exposes theemission region and the driving region opposite to a thin filmtransistor.
 22. The organic light emitting display device of claim 18,wherein the second bank pattern is disposed in the driving regionopposite to a thin film transistor.
 23. The organic light emittingdisplay device of claim 18, wherein the opening exposes the emissionregion and the driving region opposite to a capacitor.
 24. The organiclight emitting display device of claim 18, wherein the second bankpattern is disposed in the driving region opposite to an intermediateregion between a thin film transistor and a capacitor.
 25. The organiclight emitting display device of claim 18, wherein the opening exposesthe emission region and the driving region opposite to a thin filmtransistor and a capacitor.
 26. The organic light emitting displaydevice of claim 18, wherein the organic emission layer consists ofliquefied organic emission material.
 27. The organic light emittingdisplay device of claim 18, wherein the opening exposes the emissionregion and the driving region opposite to a thin film transistor and anintermediate region between the thin film transistor and a capacitor.28. An organic light emitting display device comprising: a substrateconfigured to include a sub-pixel defined into an emission region and adriving region; a first bank pattern disposed on the substrate andconfigured to define the emission region of the sub-pixel; a second bankpattern disposed on one side of the first bank pattern; an organicemission layer disposed to cover the first bank pattern.
 29. The organiclight emitting display device of claim 28, wherein the second bankpattern is disposed on a left side to the center of the first bankpattern.
 30. The organic light emitting display device of claim 28,wherein the second bank pattern is disposed on a right side to thecenter of the first bank pattern.
 31. The organic light emitting displaydevice of claim 18, wherein the second bank pattern is disposed in thedriving region opposite to a capacitor.
 32. The organic light emittingdisplay device of claim 28, wherein the second bank pattern is disposedin the driving region opposite to a thin film transistor.
 33. Theorganic light emitting display device of claim 28, wherein the secondbank pattern is disposed in the driving region opposite to anintermediate region between a thin film transistor and a capacitor.